Magnetic switch assembly for operation by magnetic cards



Oct. 21, 1969 w. w. BARNEY MAGNETIC SWITCH ASSEMBLY FOR OPERATION BYMAGNETIC CARDS Original Filed June 50, 1967 W N W m N 7 5 United StatesPatent 3,474,365 MAGNETIC SWITCH ASSEMBLY FOR OPERATION BY MAGNETICCARDS Walter W. Barney, 4837 Woodley Ave., Encino, Calif. 91316 Originalapplication June 30, 1967, Ser. No. 650,483, now Patent No. 3,430,200,dated Feb. 25, 1969. Divided and this application July 5, 1968, Ser. No.742,760 Int. Cl. H01h 9/54 U.S. Cl. 335206 6 Claims ABSTRACT OF THEDISCLOSURE A plate has a plurality of parallel openings in whichrespective axially poled magnets are slidable. The magnets are normallyurged toward one face of the magnet, as by iron rings in said one faceor by magnetic cylinders around the openings where the plate ismagnetic. Each movable magnet is adapted to be repelled by a magnet atsaid one face to engage a fixed contact at the other face of the plate.Each opening is closed at both ends to prevent contaminants enteringtherein.

CROSS-REFERENCE TO RELATED APPLICATION This application is a division ofmy application, Magnetic Card and Validator Apparatus, Serial No.650,483, filed June 30, 1967, now Patent No. 3,430,200.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to so-called magnetic card readers, and more particularly to animproved magnet operable switch and reader plate assembly employing aplurality of such switches.

Description of the prior art In devices heretofore known which employswitches operable from magnets embedded in a card, the card magnets areflat strips with their poles on lines parallel to the card faces. Themovable magnets are supported with their poles in planes parallel to thecard magnets, and are adapted for sliding or pivotal movement in suchplanes to close respective pairs of switch contacts. The direction ofmovement of such a magnet depends upon whether a card magnet adjacentthereto is in polarity opposing or attracting relation thereto.

A disadvantage in such arrangements is that a significant portion of theavailable magnetic fields linking aligned card and movable magnets isneeded to overcome magnetic force components tending to subject themovable magnets to transverse movement. In this connection, it will beseen that when relatively fixed and movable parallel magnets are broughtclose together, the movable magnet tends to be drawn toward or movedapart from the fixed magnet, depending upon whether their correspondingends are of like or opposite poles.

Still further, magnets mounted for pivotal movement have inherentbearing friction. A substantial portion of available magnetic fieldslinking aligned card and pivotal magnets necessarily is used to overcomesuch friction.

For such reasons, movable magnets frequently fail to operate properly,thereby preventing the establishment of signal information for authenticmagnetic cards. Such prior art arrangements are thus not suitable formagnetic credit and security card systems which require a high degree ofrepeatability and reliability in. operation of magnet switches inresponse to properly coded magnetic cards.

Summary of the invention My invention embraces a plate having aplurality of openings wherein respective magnets are slidable away fromone face of the plate in response to magnets in a card placed adjacentsaid one face, and means normally holding said magnets in predeterminedpositions. Further my invention embraces means closing the ends of saidopenings to prevent their exposure to dirt, moisture and the like, andalso the combination of such assembly with a card having axially poledmagnets to be aligned with the movable magnets.

I thus eliminate the prior art problems involving the loss of asignificant portion of fields of aligned card and movable magnets neededfor the task of overcoming magnetic and mechanical friction forces thatresist the desired movement of switch magnets. Further, my assembly isone in which I eliminate the likelihood of exposure of contacts to andthe contamination of contacts by dirt, moisture and the like.

Brief description of the drawing FIGURE 1 is a perspective view of aplate for supporting magnet operable switches, in accordance with myinvention;

FIGURE 2 is a fragmentary perspective view of a plate carrying aplurality of fixed contacts to be aligned with the openings in the plateof FIGURE 1;

FIGURE 3 is an enlarged sectional view of the plates of FIGURES 1 and 2assembled; and

FIGURES 4 and 5 are fragmentary sectional views of modified forms ofmagnet operable switch assemblies in accordance with my invention.

Description of illustrative embodiments Referring to FIGURES 1-3, thereis shown a nonmagnetic plate 130 having openings 132 arranged in fourrows of ten. In one face of the plate 130, grooves 134 surround aroundeach opening 132, and deposited in each groove is magnetic material 136,e.g., a ring of soft iron. The wall of each opening 132 is plated, aswith gold or silver (indicated at 138 in FIGURE 3). Slidable in eachopening 132 is a magnet 140, such magnet also being coated along itslength and on the end opposite the grooves 134.

After the magnets 140 are located in the openings 132, the face of theplate 130 in which the grooves 134 are located is covered with a sheet142 of nonmagnetic material, e.g., a thin sheet of brass or aluminum, orplastic. Also, the opposite face of the plate 130 is covered with asheet 144 of nonconductive material, e.g., plastic, which has openings146 aligned with the openings 132 in which the magnets 140 are located.The openings 146 are substantially larger in diameter than the platedmagnets 140. Thus, the plated ends of the magnets 140 can readily movethrough the openings 146, as when such a magnet is repelled by a magnetin a card 88 when the card is placed alongside the face sheet 142.

In FIGURE 3, the top tow magnets 140, the bottom magnet, 140, and thecorresponding magnets in the card 88 are so poled that the magnets 140are attracted by the magnets 80, and hence are retained against thesheet 142. However, the third magnet 80 in the card 88 has had itspolarity reversed (as by initially magnetizing all the magnets 80 in apredetermined pattern, and then coding the card by reversing thepolarities of selected ones of the magnets 80). Accordingly, the thirdmagnet 140 in FIGURE 3 is repelled, so that the plated end thereof movespast the adjacent face of the plate and through the adjacent opening 146in the plastic sheet 144.

A magnet that is subjected to such movement is brought into engagementwith an electrical contact. In this connection, and referring to FIGURE2 along with FIGURE 3, a block 150 is provided in which a plurality ofcontacts 152 are embedded. As best seen in FIGURE 3, each of thecontacts 152 is formed as a short rod-like element that extends throughthe block 150, and which has an enlarged head that is substantiallylarger in diameter than the openings 140 in the plastic sheet 144. Theblock 150 is fastened at 156 to the plate 130, so that the end faces ofthe heads of the contacts 152 are brought firmly into abutment with theadjacent face of the sheet 144. Thus, when a movable magnet 140 isrepelled by a magnet 80 in the card 88, the plated end of the magnetcomes into contact with the adjacent surface of the head of the contact152. To enhance conductive contact, the enlarged heads of the contacts152 may be similarly plated.

As will be observed, the magnets 146 are housed in a contaminant-freeenvironment. The sheet 142 on the one face of the plate 130 covers theopenings 132 in the surface. At the opposite ends of the magnets 141),the

outer ends of the openings 146 are closed by the enlarged contact 152establishes a conductive connection between i such contact 152 and theplate 131). The plate 130 is shown connected to a point of reference orground potential, and leads 119 conductively secured to the outer endsof the contacts 152 are adapted for conection to a network for providingsignal information identifiable with the card.

The soft iron rings 136 shown in FIGURE 3 serve to bias the magnets sothey are normally retracted into the late. Thus, when the card 88 isWithdrawn from adjacent the plate 131), the extended magnet 140 isretracted into the plate 130 due to the attractive force between theiron ring 136 and the adjacent end of such magnet.

FIGURE 4 illustrates a modified form of the arrangement shown in FIGURE3. In this case, the nonmagnetic plate 130 is replaced with a plate 162of magnetic material. Instead of the small openings 132 and grooves 134of the plate 130, the plate 162 is provided with relatively largeopenings 164, and cylindrical inserts 166, e.g., brass or aluminum, arepress-fit into the openings 164. The inner walls of the inserts 166 areplated at 168 and the plated magnets 14-0 are slidably mounted in theplated inserts 164. As indicated, this arrangement is one in which eachmagnet 140 is provided with a completed magnetic path through thematerial of the plate 162. In such arrangement, when such a magnet isrepelled by a magnet in a credit card, so as to make contact with thefixed contact 152, withdrawal of the card results in the magnet 140automatically being retracted to its normal position within the plate162.

FIGURE 5 illustrates a further modification wherein a plate 130' forhousing magnets 140 is made of nonmagnetic material, like the plate 130of FIGURE 3. Nonmagnetic inserts 166' are provided which are like theinserts 166 of FIGURE 4. The inserts 166 are press-fit into inserts 170of magnetic material, and these in turn are press-fit into openings 172provided in the plate 130. As will be seen, the magnetic inserts 170,like the plate 162 of FIGURE 4, provide a magnetic path for each of themagnets 140, to aid in retracting the magnets following 4 their movementinto engagement with the fixed contact 152. The plastic sheet 174covering the outer face of the plate 130' serves the same purpose as thenonmagnetic plate 142 of FIGURES 3 and 4.

From the foregoing, it will be apparent that various modifications andextensions of the above-described embodiments can be made Withoutdeparting from the spirit and scope of my invention. Accordingly, I donot intend that my invention shall be limited, except in accordance Witha reasonable interpretation of the appended claims.

I claim:

1. In combination:

a plate having a plurality of openings therethrough,

wherein portions of the plate surrounding the openings are nonmagnetic;

a fixed contact at each opening adjacent one surface of said plate;

an axially poled permanent magnet in each opening,

each magnet carryingcontact means and being axially slidable toward andaway from the associated fixed contact to elfect make and breakswitching between the fixed contact and contact means;

and magnetic bias means normally biasing each magnet to a predeterminedposition of its contact means with respect to the associated fixedcontact.

2. The combination of claim '1, wherein said plate is nonmagnetic saidplate having a groove around each opening in the surface thereofopposite said one surface;

and magnetic material disposed in each groove.

3. The combination of claim 1, wherein said plate is nonmagnetic;

and a respective magnetic cylinder in said plate surrounding eachopening.

4. The combination of claim 1, wherein said plate is magnetic;

and a nonmagnetic cylinder in said plate surrounding each Opening.

5. The combination of claim 1, including a nonconductive sheet coveringsaid one surface of said plate and having openings aligned with theopenings in said plate, said fixed contacts abutting said sheet aroundthe openings therein, the openings in said sheet being large enough topermit the associated magnets to move therethrough to engage said fixedcontacts;

and a nonmagnetic sheet overlaying the opposite surface of said plateand the grooves and the ends of the openings therein.

6. The combination of claim 5, including:

a nonconductive plate, said fixed contacts being embedded in andextending through said nonconducplate;

and means supporting said nonconductive plate with said fixed contactsabutting said nonconductive sheet.

References Cited UNITED STATES PATENTS 8/1951 Cooley 335-205 X 5/1952Cooley 335205 X 10/1964 OGorman 335-207 X

